On September 13th the main forces of the Germans retired to the high ground two miles north of the Aisne and entrenched themselves. As the British also dug themselves in, this was the beginning of trench warfare. But the combatants did not settle themselves down to it entirely for some months afterwards. There were still surprise attacks and counter-strokes, in which cavalry took a part, as is seen from an adventure of the 2nd Irish Fusiliers as told by Lance-Corporal Casement. "One night," he says, "after a very hard day in the trenches, when we were wet to the skin, and had lighted fires to dry our tunics, we heard firing along our front, and then the Germans came down on us like madmen. We had to tackle them in our shirt-sleeves. It was mainly bayonet work, and hard work at that. They were well supported by cavalry, who tried to ride us down in the dark, but we held our ground until reinforcements came up, and then we drove the enemy off with a fine rush of our horsemen and footmen combined." One of the most inspiring of the deeds of self-sacrifice which the war has produced was done by an Irish soldier. In the churchyard of a village near the Aisne is the grave of a private of the Royal Irish Regiment marked by a cross without a name, but with the arresting inscription--"He saved others; himself he could not save." The story of how this unknown hero gave his life to save others was told by a wounded corporal of the West Yorkshire Regiment in an hospital at Woolwich. On September 14th, in the concluding stage of the struggle for the Aisne, the battalion was sent ahead to occupy a little village near Rheims. "We went on through the long, narrow street," says the narrator, "and just as we were in sight of the end of it a man in khaki, to our great surprise, dashed out from a farmhouse on our right and ran towards us shouting a warning. Immediately we heard the crackle of rifles in front, and the poor chap fell dead before he reached us." The West Yorkshires ran to cover, and ultimately drove the Germans out of the houses they occupied at the outskirts of the village. Then they discovered that an ambush had been prepared into which they would have moved to their doom but for the warning given by the man in khaki at the cost of his life. He was a private of the Royal Irish Regiment--2nd battalion--who was taken prisoner the day before and confined in the farmhouse, but his identification disc had been removed by the Germans, and there was no means of discovering his name. "We buried him with military honours," concludes the narrator; "and there was not a dry eye among us as we laid him to rest."